Add qspi and opi psram binaries.
Build binary for Flix2 board.
Add config.h file for defining parameter defaults.
Set appropriate pwm frequency for c3/s3 automatically using config.h.
Remove pid parameters definitions, the may be set is config.h now.
* Move .markdownlint to the root so it applies to the main readme.
* Improve .markdownlint, enable proper names checks.
* Use markdownlint-cli2 instead of markdownlint-cli as it's more compatible with VSCode extension.
* Create book structure.
* Add workflow for linting the markdown using markdownlint.
* Add workflow for building the book with mdBook and deploying to the website.
* Restyle mdBook and support GitHub-style alerts.
* Add images zooming.
* Add index, firmware structure and gyroscope articles.
Oleg Kalachev
